Opt in ActivityStartInterceptor for BAL

PendingIntents created by the interceptor should be opted in based on
the caller to continue allowing activity starts after confirmation (that
alone indicates that the user wants the start to happen).
Currently this blocks e.g. shortcuts to unpause a paused work profile
and start the activity.

Test: manual & atest ActivityStartInterceptorTest
Bug: 314033453
Change-Id: I929ddc8dfe93298b7f03612a21a9320f5beabae8